Quick acting chuck



Oct. 6, A ARF QUICK ACTING CHUCK 3 Sheets-Sheet 1 Filed March 4, 1957 m. 1M m w |I|| r||| I, m w .4. a N l o l N////V////////////////////M///l w M liii l.- u i wllrili I w V N z ,M S @W W I mw WI Lu. W 1 l v HMV I'l MW -.111 l -v 9v ,WV N HQ I Q 5 N m Hl /lll/Ifi /ll 1. l mw, 11./ Q NN l y III Vl. ww mw im vw n. mu m- N MNHN #Trax/vars Oct. 6,1959

E. A. ARP

QUICK ACTING CHUCK 3 Sheets-Sheet 2 Filed March 4, 1957 INVENTOR. EM/ALD 4. ARP a naaMM/J/ Afrox/Veys C- 6 1959 E. A. ARP 2,907,573

QUICK ACTING CHUCK Filed March 4, 1957 5 Sheets-Sheet 3 .Fuz-E: 4 '1 INVENTOR. EA/ub 4. ARP

\\ @AMM @MM United States at QUICK ACTING CHUCK Ewald A. Arp, Minneapolis, Minn., assignor to Tobin- 4'Arp Manufacturing Company, Minneapolis, Minn., a

`corporation of Minnesota Application March 4, 1957, Serial No. 643,775

Claims. (Cl. 279-55) The inventio-n herein has relation to a chuck which can be employed for `various purposes, 1out which has been devised to be especially useful for grasping the Fig. 5 is a detail sectional View, taken as on line 5 5 in Fig. 3;

Fig. 6 is a detail sectional View, taken as on line 6 6 in Fig. 3;

Fig. 7 is a detail sectional view, on a reduced scale and parts being omitted, taken as on line 7 7 in Fig. 3; and

Fig. 8 is a transverse sectional view, on a reduced scale, taken as on line 6 3 in Fig. 3. p

A housing lll, resting as at .il on a supporting surface, rotatably supportsas by a ball bearing assembly l2, an exterior sleeve i3 of the new and improved chuck.

An end of the exterior sleeve i3, the right end in Fig. 3 of the drawings, rigidly supports, as at la, an assembly including relatively small V-tulley .l5 and `a corn-v paratively large li-pulley lo to be driven, as by a t1-belt to cause scidexterior sleeve to be rotated. j

An outlet plug Till, to be connected with a source (not shown) of electric power, is connected to conducting wires leading to an electric motor 2li suitably and conveniently supported on the housing lll. A motor shaft 2l lixedly supports a tf-pulley 2.2., and a shaft 23 fixedly supports alined tl-pulleys, denoted 24, Z5 and 26, respectively A. V-belt 27 rides the Vpulleys 22 and 24. The t-beit i7 selectively can be made to ride the Vn pulleys l5 and or the V-pulleys lo and 2u.

An interior sleeve 22B, in spaced, concentric relation to the exterior sleeve lLis mounted cen rally, as at Z9, in the hub of the small tl-pulley l5 for longitudinal sliding movement. @ne end portion, at the right in Fig.` 3 of the drawings, of said interior sleeve'extends' to posi-A tion beyond the pulley assembly at the side thereof opposite said exterior sleeve, and the other endportio'n of the interior sleeve is within and surrounded by the exterior sleeve. C l

A cylindrical portion 3l of a rst hollowactuator of the chuck is slidably mounted in the exterior sleeve 13 and iixedly cemented on the adjacent end portion of the interior sleeve 2S, and a cone shape internal surface 32 of said 'first hollow actuator is in alined, concentric relation to the inner sleeve and faces in direction away from the pulley assembly. Acompression coilspring 33, in ysurrounding relation to said interior sleeve and having its t opposite/ends seated against the hub 30 and an end surleft in Fig. 3.

An end of the exterior sleeve 23.3, at the side of the llrst hollow actuator opposite the pulley assembly, fixedly supports, as by an attaching nut 35 rotatably mounted at 35 in the housing itl, a second hollow actuator 37.

A cone shape internal surface 33 of said second hollow ctuator is in alined, concentric relation to the first hollow actuator and faces toward the cone shape internal surface Said cone shape internal surfaces 32 and 38 are of the same size and configuration as disclosed, except the cone shape internal surface 32 is cut away, as at 39, and the first hollow actuator is provided with slots '79, for a purpose to be explained. Also, the cone shape internal surfaces are in spaced relation and alinernent longitudinally ofthe exterior and interior sleeves 13 and 25.

Anv oilite metal bearing fill, suitably and conveniently secured, as at di, in the housing lll, includes an internal bearing surface l2 of conical configuration engaged by a conical external bearing surface 43 of the second hollow actuator 37. The conical bearing surfaces 42 and 133 are in alined, concentric relation to the irst and second hollow actuators and the exterior and interior sleeves i3 and 2S. A rubber nipple t4 secured, as by roll pins 45, against an external surface of the oilite bearing Il@ includes a central opening lo for snugly receiving a stem 47 of a valve i8 to be refaced.

The ball bearing assembly l2 is situated between an annular adjusting nut d@ and an annular shoulder Sti at one side thereof and a collar 5l at the opposite side of said ball bearing assembly. The annular adjusting nut is at the side of the outer raceway of the ball bearing assembly adjacent the pulley assembly and opposite the iirst and second hollow actuators and in perpendicular relation to the exterior and interior sleeves ld and 28. An externally `threaded surface 52 of said annular adjusting nut engages an internally threaded 4surface provided by the housing l0. The collar 51 is fixed upon the external surface of the exterior sleeve 13, and the annular shoulder 511i and said collar are engaged against opposed side surfaces of the inner raceway of said ball bearing assembly.

The external surface of the outer raceway of the ball bearing assembly is mounted upon a pair of nylon screws, indicated 53 and 54, respectively, and a steel ball 55 all supported by an annular portion 56 of the housing. The nylon screws and steel 1uall are situated at 120 degrees apart and said outer raceway is in slightly spaced, concentric relation to an annular internal surface of the arrn1 ai portion 56. Outer Vends of the nylon screws arel bedded in said annular portion of the housing, said, nylon screws extend radially inwardly and inner ends of the nylon screws are engaged against said external surface of said outer raceway. Expander pins 57 are `for retaining the nylon screws in fixed position. The steel ball 55 is situated in the open inner end of a hollow screw 'llambedded in the annular portion 56 of the housresists lift created by the V-belt drive, the nylon screw 54 backs up or resists force applied by a grinding wheel when operating upon a valve, such as 48, the stem of which is clamped in the chuck, and the resiliently pressed steel ball 55 maintains pressure against the nylon screws 53 and 54. The compression coil springs 60 exert force against the outer raceway of the ball bearing assembly which constantly urges the rotatable unit of the chuck toward the oilite metal bearing 40 thus to resiliently maintain the external bearing surface 43 of the second hollow actuator 37 in engagement with the internal bearing surface 42 of said oilite metal bearing regardless of wear of said external and internal bearing surfaces. The construction and arrangement including the nylon screws, the steel ball and the compression coil springs 60 is provision for, or permits, end play of the rotatable unit of the chuck rendering itself-alining with wearing of the internal and external bearing surfaces 42 and 43 of the oilite metal bearing 40 and the second hollow actuator 37, respectively.

A grasping unit of the chuck includes spaced, parallel, longitudinally extending clamping jaws, each indicated 62, slidably situated within the exterior sleeve 13 between the iirst and second hollow actuators. As disclosed, there are three clamping jaws 62 spaced at 120 degrees ap-art, and the clamping jaws are of duplicate construction. Each is constituted as a rectangular bar having its opposite end surfaces, each denoted 63, ground concentrically with the adjacent end surfaces of the other two rectangular bars so that the end surfaces of the rectangular bars at each end thereof describe a conical surface for engagement with the cone shape internal vsurfaces 32 and 38 of said first and second hollow actuators, respectively. Each end surface 63 of each clamping jaw will be of configuration to insure that the end surfaces at the `leading and at the following ends of the clamping jaws will be forced uniformly and evenly inwardly by the second and lirst hollow actuators, respectively, when said first hollow actuator is forced toward said second hollow actuator, in a manner to be set forth, to cause plane internal surfaces, each represented 64, of the rectangular portions of the clamping jaws to be forced against opposed surfaces of a valve stem, such as 47, to be clamped in the chuck. The clamping jaws 62 are insertable to and removable from their proper positions by being passed through the iirst hollow actuator, and the cut-away parts 39, between portions of the internal surface 32 engaged by the corresponding end surfaces 63 of the clamping jaws, provide clearance for ready and easy insertion and removal of the clamping jaws.

Spaced, parallel, longitudinally extending guide jaws, each represented 65, are situated between the clamping jaws 62. An external surface 66 of each guide jaw is of part-cylindrical configuration and tted against an internal surface of the exterior sleeve 13, and an internal surface 67 of each guide jaw is disposed exteriorly of innermost portions of the rectangular bars of adjacent clamping jaws 62. Opposite, longitudinally extending side surfaces 68 of each clamping jaw yare slidably engaged against adjacent longitudinally extending side surfaces of adjacent guide jaws 65. The guide jaws are shorter than the clamping jaws and the opposite ends of the guide jaws are in spaced relation to the first and second hollow actuators. The construction and arrangement are such that the guide jaws permit the clamping jaws to be moved longitudinally and radially and preclude transverse movement of said clamping jaws. Each guide jaw 65 is secured in the exterior sleeve 13 by a cap screw 69 which passes through said exterior sleeve and enters the corresponding guide jaw, and the guide jaws are maintained in longitudinal position in said exterior sleeve by guide pins 70.

A longitudinally slidable, elongated tube 71 of a valve stem stop mechanism of the chuck is situated interiorly of the interior sleeve 2S of said chuck in spaced relation thereto. A collet 72 upon said elongated tube includes an annular body having an external thread 73 thereon engaged with an internal thread at the rearward end portion, the right end portion in Fig. 3, of saidV interior sleeve. The collet extends rearwardly of the rear end of the interior sleeve and is for a purpose to be explained. An actuator sleeve 74, between the interior sleeve 28 and the elongated tube 71 and slidably engaged with both, is normally retained in a forward position by a compression coil spring 75, also between said interior sleeve and said elongated tube. A rearward end of the compression coil spring 75 is engaged, as at 76, against a forward end of the annular body of the collet 72, and a forward end of said compression coil spring is engaged, as at 77, against the rearward end of the actuator sleeve 74. A boss 78, upon the interior sleeve 28 and extending interiorly thereof, as wel-l as situated forwardly of and in spaced, longitudinally alined relation to said actuator sleeve, is for movement of the actuator sleeve rearwardly, against force of the compression coil spring 75, in response to rearward sliding movement of said interior sleeve, against force of the compression coil spring 33.

The chuck includes three lengths, each designated 80, of semi-rigid spring wire which extend longitudinally of the interior sleeve 28 and individually connect the rear ward end portions of the clamping jaws 62 to a forward end portion of the actuator sleeve 74. The lengths 80 are of duplicate construction. A forward end portion of each length is imbedded and cemented, as at 81, in the rearward end portion of a corresponding clamping jaw at a location disposed interiorly of the adjacent cone shape end portion thereof and exteriorly of the internal surface 64 of the rectangular bar thereof, and a rearward end portion of each length is imbedded and cemented, as at 82, in the forward end portion of said actuator sleeve. The rearward end portions of the lengths are in the circumference of the actuator sleeve. The lengths of spring wire are situated to be in clearing relation to valve stems which vary in shapes and sizes. The chuck has been devised to accommodate club footed valve stems, so-called. The slots 79 through the first hollow actuator are for free passage of the spring wire lengths. The lengths of spring wire maintain the rear and front ends, respectively, of the clamping jaws in planes passed perpendicularly and transversely through the rotatable unit of the chuck. The semi-rigid spring wire lengths will be tensioned to urge the clamping jaws 62 and their forward and rearward end portions outwardly.

A rearward end portion of the elongated tube 71 of the valve stem stop mechanism extends rearwardly of the rear end of the collet 72 and is externally knurled, as at 83. A bushing 84 is fixed within the forward end portion ofel i said elongated tube. A straight elongated rod 85 is longitudinally slidable in the bushing 84, a lock nut 86 is for releasably securing the elongated rod in fixed relation to :j the elongated tube and a retaining element 87, on the rigidly supports a stop piece 89 to be engaged by the rear or free ends of the stems of valves to be refaced. As disclosed, the member 88 is constituted as a collapsed coil of wire having its rear end portion iixedly secured n upon a cylindrical stud 90 projecting forwardly from the elongated rod 85, its rear end engaged against an annular shoulder 91 of said elongated rod in surrounding relation to the cylindrical stud 90, its front end portion lixedly secured upon a cylindrical stud 92 Vprojecting rearwardly from the stop piece 89 and its front end engaged against an annular shoulder 93 of said stop piece' in surrounding` i elongated tube.

felation to the cylindrical stud 92. The member 88 and thread 73 and forwardly of the spaced jaws 94. An annular wedge 98, within the hollow lock nut, includes a cylindrical external surface engageable with the internal surface of the side wall of said hollow lock nut and a cone `shaped internal surface 99 engageable with tapered external surfaces of the spaced jaws 94. Steel balls 100 are situated within the hollow lock nut between the rear end of the annular wedge 98 and an end wall 101 of said hollow lock nut. An opening through said end Wall is for freely receiving said elongated tube. The valve stem stop mechanism, constituted as the elongated tube 71 with knurl 83, the bushing 84, the lock nut 86, the elongated rod 85, the member 88 and the stop piece 89 can be longitudinally slidable in, readily removable from and replaceable in the collet 72 and the actuator sleeve 74, by turning the hollow lock nut 95 to relieve pressure of the spaced jaws 94 of said collet against the external surface of said elongated tube, and said valve stop mechanism can be '.fixedly secured within the collet at any position to which longitudinally adjusted by turning said hollow lock nut to constrict said spaced jaws 94 and cause them to be pressingly engaged against said external surface of the Also, the valve stem stop mechanism can be lengthened or shortened by removing the lock nut 86 from engaged relation with the elongated rod 85, slidably adjusting said elongated rod in the bushing 84 and turning said lock nut down against the elongated rod after adjustment is made.

A cylindrical shell 102 is supported on the external surface of the exterior sleeve 13 for longitudinal sliding movement, and diametrically opposed screw bolts 103, in elongated slots 104 in said exterior sleeve, secure the cylindrical portion 31 of the first hollow actuator and the interior sleeve 28 to each other and also connect said cylindrical shell to said rst hollow actuator and interior sleeve. The heads of the screw bolts 103 are fitted in openings in the cylindrical shell 102, and the bodies of said screw bolts are fitted in openings in the first hollow actuator and the interior sleeve. The external surface of an end portion of the cylindrical shell 102, between the screw bolts 103 and the ball bearing assembly 12, ixedly supports an annular member 105 which is rectangular in cross section` as shown.

The compression coil spring 33 normally resiliently` urges the cone shape internal surface 32 of the first hollow actuator toward the cone shape internal surface 38 of the second hollow actuator. A construction and arrangement for sliding said first hollow actuator and the interior ber 109 of arc shape at a lower portion of the housing in spaced relation to the exterior sleeve. An arm 110, rigid `with the swingable member 109 and extending upwardly from one of the trunnions 106, supports a shank 111 disposed in spaced relation to and parallelly of the trunnions. Said shank supports a roller 112` engageable against a surface 113 of the annular member 105 at the side. thereof adjacent the grasping unit and opposite the pulley assembly. A handle 114 for rotatably actuating the arm 110 is secured, as at 115, to a projecting end of 6 the adjacent trunniori. Means fordeta'chably locking the handle 114 in set position is denoted generally at 116. Said handle is manually manipulatable to forcibly move the roller 112 toward the right in Fig. 3 thus to move the iii-st hollow actuator land the cone shape internal surface 32 thereof in direction away from the second hollow actuator and its cone shape internal surface 38.

In Fig. 3 of the drawings, the conical end surfaces 63 at the opposite ends of the clamping jaws 62 are resiliently engaged against the conical internal surfaces 32 and 38 of the first and second hollow actuators, respectively, and the internal surfaces 64 of said clamping jaws are resiliently engaged against opposed portions of the external surface of the valve stern 47 under force exerted by the compression coil spring 33. The longitudinally alined, conical internal surface 32 and 38 converge in di rection away from the clamping jaws and said clamping jaws when not confined are free to move longitudinally in the exterior sleeve 13. The compression coil spring 33 exerts resilient pressure in equal amount to all of the conical end surfaces 63 at each end of the clamping jaws when in confining relation thereto, and the force of said compression coil spring causes all of the internal surfaces 64 of the clamping jaws to be pressed under equal force against longitudinally extending external surfaces of valve stems, such as 47, of valves, such as 48, while being refaced. The exterior and interior sleeves 13 and 28, the clamping jaws`62, the guide jaws 65, the cylindrical shell 102, the valve stem stop mechanism and appurtenant parts rotate as a unit.

The boss 78, upon and extending interiorly of the interior sleeve 28, engages the forward end of the actuator sleeve 74 upon sliding withdrawal of the first hollow actuator from the adjacent conical end surfaces 63 of the clamping jaws 62 and causes said actuator sleeve to be slid rearwardly against force of the compression coil spring 75. Withdrawal of said first hollow actuator is accomplished by manual manipulation of the handle 114 against force of the compression coil spring 33. The clamping jaws 62 are of course moved rearwardly, through the instrumentality of the lengths of spring wire, with the actuator sleeve 74 as this is slid rearwardly.

The compression coil spring 33 acts upon release of the handle 114 from the locking means 116 to force the rst hollow actuator toward the second hollow actuator. The compression coil spring 75 acts upon release of said handle to force the actuator sleeve 74 forwardly to position where engaging the forward conical end surfaces 63 of the clamping jaws 62 against the conical internal surfaces 38 of the second actuator and the internal surfaces 64 of said clamping jaws against the valve stem before the compression coil spring 33 causes the conical internal surface 32 of the first actuator to become engaged against the rearward conical end surfaces 63 of said clamping jaws. The boss 78 moves forwardly with the interior sleeve 28 as this is forced forwardly by the compression coil spring 33, thus to permit forward movement of the actuator sleeve 74, and forward movement of said actuator sleeve causes the clamping jaws 62 to be forced forwardly through the instrumentality of the lengths 80 of spring wire. The conical internal surfaces 32 and 38 of the first and second hollow actuators become seated against the rearward and forward conical end surfaces, respectively, of the clamping jaws and the internal surfaces 64 of said clamping jaws become seated against a valve stem in response to forward movement of said rst hollow actuator after the forward conical end surfaces of said clamping jaws have become engaged against the conical internal surface 38 of the second hollow actuator. The compression coil spring 75, the actuator sleeve 74 and the lengths 80 of spring wire function to situate the forward conical end surfaces 63 of the clamping jaws 62 against the conical internal surface 38 of the second hollow actuator and said clamping jaws in a predetermined set position to be properly graspedV against a valve stem, and the compression coil spring 33 is actuable immediately after said clamping jaws are so situated and set to anism. When the length of said stop mechanism is to be altered, made longer for shorter valve stems and shorter for longer valve stems, the hollow lock nut 95 will be Vrotated to release the elongated tube '7l and the stop mechanism will be withdrawn from the chuck, the elongated rod 85 will be adjusted longitudinally of said elongated tube, inwardly or outwardly as the case may be, while the lock nut 86 is released from said elongated rod,

Asaid lock nut will be tightened down after adjustment is made, and said stop mechanism will be replaced and secured in fixed position by rotating said hollow lock nut to cause the elongated tube to be grasped. The member or collapsed wire 88 of the valve stem stop mechanism is of structure to be flexible laterally in order that it will be swung sidewise should the rear or free end portion of a valve stem unintentionally become situated at a side of the stop piece S9. Were the working end portion of the valve stem stop mechanism rigid, it could become broken by reason of the accidental insertion of the rear or free end portion of a valve stem past the stop piece, as when the valve stem was of comparatively small diameter. Said valve stem stop mechanism is supported in the chuck to situate the member or collapsible wire Sfi and the stop piece 89 at the longitudinal center of the eX- terior and interior sleeves 13 and 28.

What is claimed is:

1. In a chuck,.s'paced, longitudinally alined, first and second hollow actuators, transversely spaced clamping jaws each including first and second opposite end surfaces situated betweensaid first and second hollow actuators, the first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, first means actuable to engage the second end surfaces of the clamping jaws against the tapered internal surface of said second hollow actuator, and second means actuable after said first means has operated to engage the tapered in ternal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the first and second hollow actuators to be forcibly seated against said first and second end surfaces, respectively, of the clamping jaws in confining relation thereto.

2. In a chuck, spaced, longitudinally alined, first and second hollow actuators, transversely spaced clamping jaws each including first and second opposite end surfaces situated between said first and second hollow actuators, the 'first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, first resilient means actuable to engage the second end surfaces of the clamping jalws against the tapered internal surface of said second hollow actuator, and second resilient means actuable after said first resilient means has operated to engage the tapered internal surface of said first hollow jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said first and second end surfaces, respectively7 of the clamping jaws in confining relation thereto.

3. In a chuck, spaced, longitudinally alined, first and second hollow actuators, transversely spaced clamping jaws each including first and second opposite end surfaces situated between said first and second hoflow actuators,

` actuator against the first end surfaces of said clamping the first and second hollow actuators having tapered internal surfaces converging away from said first and'second end surfaces, respectively, of said lclamping jaws, a device operable to withdraw the clamping jaws and the second end surfaces thereof from the tapered internal surface of the second hollow actuator and the first hollow actuator and the tapered in-ternal surface thereof from the first end ,surfaces of said clamping jaws and to retain the clamping jaws and said first hollow actuator in withdrawn position, said device also -being operable to release said clamping jaws and the first hollow actuator, first means actuable upon release of the clamping jaws and the said first hollowl actuator to engage the second end surfaces of said clamping jaws against the tapered internal surface of said second hollow actuator, and second means actuable after said first means has operated to engage the tapered internal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly'seated against said first and second end surfaces, respectively, of the clamping jaws in confining relation thereto.

4. in a chuck, spaced, longitudinally alined, first and second hollow actuators, transversely spaced clamping jaws each including first and second opposite end surfaces situated between said first and second hollow actuators, the first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, a device operable to withdraw the clamping jaws and the second end surfaces thereof from the tapered internal surface of the second hollow actuator and the first hollow actuator and the tapered internal surface thereof from the first end su1faces of said clamping jaws and to retain the clamping jaws and said first hollow actuator in withdrawn position, said device also being'operable Ato release said clamping jaws and the first hollow actuator, a first compression coil spring actuable upon release of the clamping jaws and said first hollow actuator to engage the second end surfaces of said clamping jaws against the tapered internal surface of said second hollow actuator, j

and a second compression coil spring actuable after said first compression coil spring has operated to engage the tapered internal surface of said rst hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said first and second end surfaces, respectively, ofthe clamping jaws in confining relation thereto. l 5. In a chuck, an elongated exterior member, an elongated interior member mounted in said exterior member in spaced, concentric relation thereto for longitudinal sliding movement, a first hollow actuator rigid wi-th said in:` terior member, a second hollow actuator fixed against"- longitudinal movement relative to said exterior member and longitudinally alined with said first hollow actuator, transversely spaced yclarnping jaws each including Vfirst and second opposite end surfaces situated within the eX- terior member between Vsaid first and second hollow actuators, the first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, means including a first compression coill spr-ing within ysaid interior member as part thereof actuable to slide the clamping jaws toward said second hollow actuator and engage the second end surfaces of said clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil spring surrounding the interior member actuable after said first compression coil spring has operated to slide the first hollow actuator toward the clamping jaws and engage the tapered internal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators vto be forciblyjseated against said first and second end surj faces, respectively, of the clamping jaws in confining rel'ation thereto, and a device operable against force of said first and second compression coil springs to withdraw the clamping jaws and the second end surfaces thereof from the tapered internal surface of the second hollow actuator and the first hollow actuator and Ithe tapered internal surface thereof from the first internal surfaces of said clamping jaws and to retain the clamping jaws and first hollow actuator in withdrawn position, said device also being operable to release said clamping jaws and first hollow `actuator to action of said first and second compression coil springs.

6. In a chuck, an elongated exterior member, an elongated interior member mounted in said exterior member in spaced, concentric relation thereto for longitudinal sliding movement, a first hollow actuator rigidwith said interior member, a second hollow actuator fixed against longitudinal movement relative to said exterior member and longitudinally alined with said first hollow actuator, transversely spaced clamping jaws each including first and `second opposite end surfaces situated within the exterior a member between said first and second hollow actuators, :the first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, a longitudinally slidable sleeve within said interior member, a length of spring wire extending between the first end surface of each of said clamping jaws and said sleeve and connecting the clamping jaws and sleeve to each other, an element rigid with and extending interiorly of the interior member at a location between the sleeve and clamping jaws, a first compression coil spring within said interior member actuable to move said sleeves, lengths of wire and clamping jaws toward said second hollow actuator and l engage the second end surfaces of the clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil spring surrounding the interior member actuable after said first compression coil spring has operated to move the first hollow actuator toward the clamping jaws and engage the tapered internal surface of said rst hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said first'and second end surfaces, respectively, of the clamping jaws in confining relation thereto, anda device operable against force of said first and second compression coil springs to cause said element to engage said sleeve and move it away from the second hollow actuator thus to withdraw the second end surfaces of said clamping jaws from the tapered internal surface of said second hollow actuator, to withdraw the first hollow actuator and the tapered internal surface Jthereof from the first end surfaces of the clamping jaws -1 and to retain said clamping jaws and rst hollow actuator in withdrawn position, said device also being operable to release the clamping jaws and first hollow actuator to action of said first and second compression coil springs.

7. In a chuck, an elongated exterior member, an elongated interior member mounted in said exterior member in spaced, concentric relation thereto for longitudinal sliding movement, a first hollow actuator rigid with said interior member, a second hollow actuator fixed against longitudinal movement relative to said exterior member and longitudinally alined with said first hollow actuator, transversely spaced clamping jaws each including first and second opposite end surfaces situated within the exterior member between said first and second hollow actuators, transversely spaced guides secured interiorly to said exterior member and situated between said clamping jaws, the clamping jaws being slidable longitudinally and radially of said guides, the first and second hollow actuators having tapered internal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, means including a first compression coil spring within said interior member as part thereof actuable 10. to slide the clamping' jaws toward said seiid hollow tuator and engage the second end surfaces of said clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil spring surrounding the interior member actuable after said first compression coil spring has operated to slide the first hollow actuator toward the clamping jaws and engage the tapered internal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said rst and second end surfaces, respectively, of the clamping jaws in confining relation thereto, and a device operable against force of said first and second compression coil springs to withdraw the clamping jaws and the second end surfaces thereof from the tapered internal surface of the second hollow actuator and the rst hollow actuator and the tapered internal surface thereof from the first internal surfaces of said clamping jaws and to retain the clamping jaws and first hollow actuator in withdrawn position, said device also being operable to release said clamping jaws and first hollow actuator to action of said first and second compression coil springs.

8. In a chuck, an elongated exterior member, an elongated interior member mounted in said exterior member in spaced, concentric relation thereto for longitudinal sliding movement, a first hollow actuator rigid with said interior member, a second hollow actuator fixed against longitudinal movement relative to said exterior member and longitudinally alined with said first hollow actuator, transversely spaced clamping jaws each including first and second opposite end surfaces situated within the exterior member between said first and second hollow actuators, transversely spaced guides secured interiorly to said exterior member and situated between said clamping jaws, the clamping jaws being slidable longitudinally and radially of said guides, the first and second hollow actuators having tapered internal surfaces converging away from said first and second endl surfaces, respectively, of said clamping jaws, a longitudinally slidable sleeve within said interior member, a length of spring wire extending between ithe first end surface of each of said clamping jaws and said sleeve and connecting the clamping jaws and sleeve to each other, an element rigid with and extending interiorly of the interior member at a location between the sleeve and clamping jaws, a first compression coil spring within said interior member actuable to move said sleeve, lengths of wire and clamping jaws toward said second hollow actuator `and engage the second end surfaces of the clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil spring surrounding the interior member actuable after said first compression coil spring has operated to move the first hollow actuator toward the clamping jaws :and engage the tapered internal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said first and second end surfaces, respectively, of the clamping jaws in confining relation thereto, and a `device operable against force of said first and second compression coil springs to cause said element to engage said sleeve and move it away from the second hollow actuator thus to withdraw the second end surfaces of said clamping jaws from the tapered internal surface of said. second hollow actuator, to withdraw the first hollow actuator and the tapered internal surface thereof from the first end surfaces of the clamping jaws and to retain said clamping jaws andv first hollow actuator in withdrawn position, said device; also being operable to release the clamping jaws and first hollow actuator to action of said first and second com-- pression coil springs.

9. In a chuck, an elongated exterior member, an elon-- gated interior member mounted in said exterior memberin spaced, concentric relation thereto for longitudinal slid-` ing movement, a first hollow actuator rigid with said interior member, a second hollow actuator fixed against longitudinal movement relative to said exterior member and longitudinally alined with said first hollow actuator, transversely spaced clamping jaws each including first and second opposite end surfaces situated within the exterior member between said first and second hollow actuators, the 'first and second hollow actuators having tapered internal surfaces converging away' from said first and second end surfaces, respectively, of said clamping jaws, a first compression coil spring actuable to move the clamping jaws ltoward said second hollow actuator and engage the second end surfaces of said clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil springactuable after said first compression coil spring has operated to 'move the -first' hollow actuator toward the clamping jaws and engage the tapered internal surface of said first hollow actuator Vagainst the first end surfaces of said clamping vjaws and cause the tapered internal surfaces of the first and second hollow actuators to be forcibly seated against said first and second end surfaces, respectively, of the clamping `jaws in confining relation thereto, and a device operable against force of said first and second compression coil springs to withdraw the clamping jaws from the tapered internal surface of the second hollow actuator and the first hollow actuator from the first end surfaces of said clamping jaws and to retain the clamping jaws and first hollow actuator in withdrawn position, said device also being operable to release said clamping jaws to the action of said first compression coil spring and said first hollow actuator to the action of said second compression coil spring.

10. In a chuck, an elongated exterior member, an elongated interior member mounted in said exterior member `'in spaced, Vconcentric relation thereto for longitudinal slid- .ternal surfaces converging away from said first and second end surfaces, respectively, of said clamping jaws, a longitudinally sildable sleeve, a length of wire extending between the first end surface of each of said clamping jaws and said sleeve and connecting the clamping jaws and sleeve to each other, an element rigid with said interior member at a location between said sleeve and clamping jaws, a first compression coil spring acruable to move said sleeve, lengths of wire and clamping jaws toward said second hollow actuator and engage the second end surfaces of the clamping jaws against the tapered internal surface of the second hollow actuator, a second compression coil spring actuable after said `first compression coil spring has operated to movethe first hollow actuator toward the clamping jaws and' engage the tapered internal surface of said first hollow actuator against the first end surfaces of said clamping jaws and cause the tapered interrr'al surfaces'of the fnst and'second hollow actuators to be forcibly seated against said first and second end surfaces, respectively, of the clamping jawsfin confining'relation thereto, and a device operable tocause'said element to engage said sleeve and move it awayffrom the, second hollow :actuator thus to withdraw the second end surfaces of said clamping jaws from the tapered internal surface of said second hollow actuator, to withdraw the lirsthollow actuator and the tapered Vinternal surface thereof from tbe rfirst end surfaces of the clamping jaws and to retain said clamping jaws and first hollow actuator in withdrawn position, said device also being operable to release said clamping jaws to the action of said first compression coil spring and said first hollow actuator to the action of said second compression coil spring.

'References tilted in the file of this patent UNTED STATES PATENTS 

